[shotwell] Fix .desktop file generation

[Jens Georg <jensgeorg src gnome org>]

commit 255a39c9e5c9df94bc16f2988ac50f9bc6dd9866
Author: Jens Georg <mail jensge org>
Date:   Fri Jul 22 22:18:24 2016 +0200

    Fix .desktop file generation
    
    Fixes https://bugs.archlinux.org/task/50129
    
    Signed-off-by: Jens Georg <mail jensge org>

 misc/Makefile.am |   10 ++++------
 1 files changed, 4 insertions(+), 6 deletions(-)
---
diff --git a/misc/Makefile.am b/misc/Makefile.am
index 6804401..6376879 100644
--- a/misc/Makefile.am
+++ b/misc/Makefile.am
@@ -7,19 +7,17 @@ appdata_XML = \
        shotwell.appdata.xml
 
 desktopdir = $(datadir)/applications
-desktop_in_files = shotwell.desktop.in shotwell-viewer.desktop.in
 desktop_DATA = shotwell.desktop shotwell-viewer.desktop
 
 $(appdata_XML) : $(appdata_in_files)
        $(AM_V_GEN) $(MSGFMT) --xml --template $< -d $(top_srcdir)/po -o $@
 
-$(desktop_in_files): $(srcdir)/shotwell.desktop.in.in $(srcdir)/shotwell-viewer.desktop.in.in
-       $(AM_V_GEN) $(MSGFMT) --desktop --template $< -d $(top_srcdir)/po -o $@
-
-# Substitute variables in a Desktop Entry file.
-$(desktop_DATA): $(desktop_in_files)
+%.desktop.in : %.desktop.in.in
        $(AM_V_GEN) sed -e 's|@VERSION[@]|$(VERSION)|g' $< > $@
 
+%.desktop : %.desktop.in
+       $(AM_V_GEN) $(MSGFMT) --desktop --template $< -d $(top_srcdir)/po -o $@
+
 @GSETTINGS_RULES@
 @APPDATA_XML_RULES@